Re: Complement replacement

*To*: mathgroup at smc.vnet.net*Subject*: [mg58628] Re: [mg58608] Complement replacement*From*: yehuda ben-shimol <bsyehuda at gmail.com>*Date*: Sun, 10 Jul 2005 16:51:51 -0400 (EDT)*References*: <200507100912.FAA06500@smc.vnet.net>*Reply-to*: yehuda ben-shimol <bsyehuda at gmail.com>*Sender*: owner-wri-mathgroup at wolfram.com

Hi, I suspect that from the solutions offered below you mean the procedural oriented paradigm which is given by the last solution. note, that fisrt it is recommended to Sort[] your table. This is usually done in O(n Log[2,n]) run time complexity and will improve any solution that you will choose to use later. I'm also sure that you will get many other solutions and approaches For the code offered below, the result is given in variable res, and the rest is to compare the run time (ignoring sorting that all rely on). sp = Sort[pp = Array[Random[Integer, {1, 1000}] &, 1000]]; (res = Table[If[! MemberQ[sp, i], i], {i, 1000}] // Union // Most) // Timing // First (res = Reap[Do[If[! MemberQ[sp, i], Sow[i]], {i, 1000}]] // Rest // Flatten) // Timing // First (res = Reap[Do[If[! MemberQ[sp, i], Sow[i]], {i, 1000}]] // Rest // Flatten) // Timing // First k = 1; (res = Rest[Reap[(While[k < #, If[++k < #, Sow[k]]]) & /@ sp]] // First // Flatten) // Timing // First The running times that I got on my computer for the specific example genrated by the rundom numbers are: 0.22 Second 0.191 Second 0.18 Second 0.01 Second yehuda On 7/10/05, konstantpi at mail15.com <konstantpi at mail15.com> wrote: > hi > in the list: > pp=Table[Random[Integer, {1, 1000}], {i, 1000}]; > how could i know which numbers from 1 to 1000 does not exist in the > pp List. > but without using: > Complement[Table[i,{i,1000}],pp] > regards > >

**References**:**Complement replacement***From:*konstantpi@mail15.com